Some evidence is emerging on the benefits of a few complementary approaches to Irritable Bowel Syndrome (IBS). This is a chronic condition of the large intestine that can cause abdominal pain, cramping, constipation, and diarrhea. The National Center for Complementary and Integrative Health (NCCIH) details the available evidence here including some practices that studies suggest may have some modest benefits including gut-directed hypnotherapy, acupuncture, some probiotics, and peppermint oil.